What is Kernel?

Ankur Kulhari

Explanation of the meaning of Kernel: Kernel is the core module of an operating system, which is always running. It is loaded first on booting of the system and retain in main memory of the computer system. It provides all essential operations /services those are needed by applications. Kernel takes the responsibility of managing the resources, i.e. memory, task, disk …

What is a named pipe?

Ankur Kulhari

A connection used to transfer data between separate processes to incorporate Inter Process Communication, usually on separate computers and are special files placed in the /dev directory; It is a pipe that an application opens by name in order to write data into or read data from the pipe. A named pipe is an extension of the concept ‘pipe’ in …

What is priority inversion?

Ankur Kulhari

In scheduling When a high priority task is preempted by a lower priority task, is called as priority inversion and is a problematic scenario, effectively “inverting” the relative priorities of the two tasks, violating the priority model that high priority tasks can only be prevented from running by higher priority tasks and briefly by low priority tasks nearly about to …

What is priority inheritance?

Ankur Kulhari

Consider three jobs: Job Name Priority H High M Medium L Low Suppose H is blocked by L for some shared resource. The priority inheritance protocol requires that L executes its critical section at H’s (high) priority. As a result, M will be unable to preempt L and will be blocked. That is, the higher-priority job M must wait for …

What is spin lock?

Ankur Kulhari

Locks are used in operating system to reserve critical section resources for mutual exclusion. Suppose a task is running and a little time (execution time) is left for its completion, That is: The running time left for it is less compared to the time that would be taken in blocking it and context switching. Under this situation it is not …

What is the difference between Swapping and Paging?

Ankur Kulhari

Swapping is a technique, used by medium term scheduler to send processes in waiting state from main memory to backing storage (called swap-out) and to bring processes which are ready to execute back into main memory from backing storage. Paging is a technique of memory management to allocate non-contiguous memory to a process. A process is divided into pages and …

Compare short term scheduler, medium term scheduler and long term scheduler.

Ankur Kulhari

S.N. Long-Term Scheduler Short-Term Scheduler Medium-Term Scheduler It is a job scheduler It is a CPU scheduler It is a process swapping scheduler. Speed is lesser than short term scheduler Speed is fastest among other two Speed is in between both short and long term scheduler. It controls the degree of multiprogramming It provides lesser control over degree of multiprogramming …

Static vs Dynamic Loading

Ankur Kulhari

Selection of Static or Dynamic Loading is made by developer at the time of computer program being developed. In case of static loading, the complete program is compiled and linked without leaving any external program or module dependency at the time of compilation. With static loading, the absolute program (and data) is loaded into memory in order for execution to …

Difference between computer architecture and computer organization?

Ankur Kulhari

Computer organization is about organization of all hardware devices into a system where as, architecture explains about the functions of hardware devices. The architecture indicates its hardware whereas, the organization reveals its performance. For designing a computer, its architecture is fixed first and then its organization is decided.